Isaac is born according to promise, and grows to be weaned. "The Lord had visited Sarah." It is possible that this event may have occurred before the patriarchal pair arrived in Gerar. To visit, is to draw near to a person for the purpose of either chastising or conferring a favor. The Lord had been faithful to his gracious promise to Sarah. "He did as he had spoken." The object of the visit was accomplished. In due time she bears a son, whom Abraham, in accordance with the divine command, calls Isaac, and circumcises on the eighth day. Abraham was now a hundred years old, and therefore Isaac was born thirty years after the call. Sarah expressed her grateful wonder in two somewhat poetic strains. The first, consisting of two sentences, turns on the word laugh. This is no longer the laugh of delight mingled with doubt, but that of wonder and joy at the power of the Lord overcoming the impotence of the aged mother. The second strain of three sentences turns upon the object of this admiring joy. The event that nobody ever expected to hear announced to Abraham, has nevertheless taken place; "for I have borne him a son in his old age." The time of weaning, the second step of the child to individual existence, at length arrives, and the household of Abraham make merry, as was wont, on the festive occasion. The infant was usually weaned in the second or third year 1 Samuel 1:22-24; 2 Chronicles 31:16. The child seems to have remained for the first five years under the special care of the mother Leviticus 27:6. The son then came under the management of the father.

The Lord visited Sarah - That is, God fulfilled his promise to Sarah by giving her, at the advanced age of ninety, power to conceive and bring forth a son.

And the Lord visited Sarah as he had said,.... To Abraham, Genesis 17:16; in a way of mercy and kindness, by fulfilling his promise, giving strength to conceive and bear a child; see 1 Samuel 2:21,

and the Lord did unto Sarah as he had spoken; which intends the same thing in different words; and the repetition is made to cause attention to God's fulfilment of his promise, who is always faithful to his word, even in things very difficult and seemingly impossible, as in the present case: hence the Targums of Jonathan and Jerusalem paraphrase it, God did a wonder or wonders for Sarah in causing her to conceive when she was so old, and in such circumstances as she was.

Birth of Isaac. - Jehovah did for Sarah what God had promised in Genesis 17:6 (cf. Genesis 18:14): she conceived, and at the time appointed bore a son to Abraham, when he was 100 years old. Abraham gave it the name of Jizchak (or Isaac), and circumcised it on the eighth day. The name for the promised son had been selected by God, in connection with Abraham's laughing (Genesis 17:17 and Genesis 17:19), to indicate the nature of his birth and existence. For as his laughing sprang from the contrast between the idea and the reality; so through a miracle of grace the birth of Isaac gave effect to this contrast between the promise of God and the pledge of its fulfilment on the one hand, and the incapacity of Abraham for begetting children, and of Sarah for bearing them, on the other; and through this name, Isaac was designated as the fruit of omnipotent grace working against and above the forces of nature. Sarah also, who had previously laughed with unbelief at the divine promise (Genesis 18:12), found a reason in the now accomplished birth of the promised son for laughing with joyous amazement; so that she exclaimed, with evident allusion to his name, "A laughing hath God prepared for me; every one who hears it will laugh to me" (i.e., will rejoice with me, in amazement at the blessing of God which has come upon me even in my old age), and gave a fitting expression to the joy of her heart, in this inspired tristich (Genesis 21:7): "Who would have said unto Abraham: Sarah is giving suck; for I have born a son to his old age." מלּל is the poetic word for דּבּר, and מי before the perfect has the sense of - whoever has said, which we should express as a subjunctive; cf. 2 Kings 20:9; Psalm 11:3, etc.

And the LORD visited Sarah as he had said, and the LORD did unto Sarah as he had spoken.

CHAPTER 21

Ge 21:1-13. Birth of Isaac.

1. the Lord visited Sarah-The language of the historian seems designedly chosen to magnify the power of God as well as His faithfulness to His promise. It was God's grace that brought about that event, as well as the raising of spiritual children to Abraham, of which the birth of this son was typical [Calvin].

21:1-8 Few under the Old Testament were brought into the world with such expectations as Isaac. He was in this a type of Christ, that Seed which the holy God so long promised, and holy men so long expected. He was born according to the promise, at the set time of which God had spoken. God's promised mercies will certainly come at the time which He sets, and that is the best time. Isaac means laughter, and there was good reason for the name, ch. 17:17; 18:13. When the Sun of comfort is risen upon the soul, it is good to remember how welcome the dawning of the day was. When Sarah received the promise, she laughed with distrust and doubt. When God gives us the mercies we began to despair of, we ought to remember with sorrow and shame our sinful distrust of his power and promise, when we were in pursuit of them. This mercy filled Sarah with joy and wonder. God's favours to his covenant people are such as surpass their own and others' thoughts and expectations: who could imagine that he should do so much for those that deserve so little, nay, for those that deserve so ill? Who would have said that God should send his Son to die for us, his Spirit to make us holy, his angels to attend us? Who would have said that such great sins should be pardoned, such mean services accepted, and such worthless worms taken into covenant? A short account of Isaac's infancy is given. God's blessing upon the nursing of children, and the preservation of them through the perils of the infant age, are to be acknowledged as signal instances of the care and tenderness of the Divine providence. See Ps 22:9,10; Ho 11:1,2.